Tax & Currency Settings
To edit tax and currency settings click on Settings on the admin
menu and click the Taxes & Currency link.
Tax Rates
To add a new tax rate simply enter the percentage value and click
the [Add Tax Rate] button.
To remove a tax rate simply select it and click the [Remove Selected
Rates] button. You can select multiple tax rates by holding [CTRL] on
your keyboard.
Note that products will retain their current tax rate even if it is
removed here. So you may need to modify each product or batch
update multiple products with a new tax rate.
Price Settings
Here you can change the currency for your product prices and
orders etc.
If you are selling products business to business then you might want
to display your prices excluding tax. To do this check the B2B
check-box. If you are selling to general consumers it is usually better
to leave this unchecked and display your prices with tax included.
CMS Help - Tax & Currency Settings